From 3863dff0c3dd72984395c93b12383b393c5c3989 Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Tue, 24 Jan 2017 14:06:48 +0100 Subject: [PATCH] kvm: fix usage of uninit spinlock in avic_vm_destroy() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If avic is not enabled, avic_vm_init() does nothing and returns early. However, avic_vm_destroy() still tries to destroy what hasn't been created. The only bad consequence of this now is that avic_vm_destroy() uses svm_vm_data_hash_lock that hasn't been initialized (and is not meant to be used at all if avic is not enabled). Return early from avic_vm_destroy() if avic is not enabled. It has nothing to destroy. Signed-off-by: Dmitry Vyukov Cc: Joerg Roedel Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: David Hildenbrand Cc: kvm@vger.kernel.org Cc: syzkaller@googlegroups.com Reviewed-by: David Hildenbrand Signed-off-by: Radim Krčmář --- arch/x86/kvm/svm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index d1efe2c62b3f..5fba70646c32 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1379,6 +1379,9 @@ static void avic_vm_destroy(struct kvm *kvm) unsigned long flags; struct kvm_arch *vm_data = &kvm->arch; + if (!avic) + return; + avic_free_vm_id(vm_data->avic_vm_id); if (vm_data->avic_logical_id_table_page)